Thanks everyone.

I THINK we may have solved this. She texted me yesterday, to which I replied something like, "You've been told not to text me." She said she'd continue until I gave into a demand of hers, which is essentially to argue with her. My mom texted her from her own phone telling her to stop texting me, and she replied with a defiant "no" again. So my mom called her and told her personally to stop texting or we'd involve the police.

This didn't get to her. I got one more text from her, so my dad called and spoke to her dad, who alternated between "Why won't your daughter just talk to my daughter?" and "This is an issue between the kids." Nevertheless, after he hollered at my dad and called my mom names, he DID seem to assure my dad that this girl wouldn't contact me anymore.

I got a text from her saying she wouldn't text me ever again, but that she wishes my family would be mature. She also wants us to realize we've done something very wrong.

So now it's a waiting game. Our options if she chooses to text me again are either a restraining order or a new phone, which are roughly in the same price range. It's all up to luck now.